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排序方式: 共有299条查询结果,搜索用时 30 毫秒
81.
植物多样性的分子生物学研究方法 总被引:4,自引:0,他引:4
植物多样性是生物多样性的基础,它的保护和可持续利用是维持全球经济健康发展、全球气候稳定的重要因素之一,也是保持我们赖以生存环境的重要内容。对植物多样性的分子生物学研究方法进行了综述,并着重介绍了分子标记的最新进展及其在植物多样性研究中的广泛应用。 相似文献
82.
以光引发剂二乙基二硫代氨基甲酸钠对硅胶表面进行修饰,以氨基比林为模板分子、甲基丙烯酸为单体、乙二醇二甲基丙烯酸酯为交联剂,在修饰后的硅胶表面接枝共聚制备分子印迹聚合物。利用红外光谱、电镜对聚合物进行了表征,用紫外分光光度法考察了分子印迹聚合物对氨基比林的吸附特性。结果表明,印迹聚合物对模板分子具有较高的吸附能力和选择识别能力。 相似文献
83.
Gülsen Yilmaz Fatma Meriç Yilmaz Mehmet Senes Dogan Yucel 《Indian journal of clinical biochemistry : IJCB》2007,22(1):52-56
Serum tumor markers may be requested inappropriately by clinicians. In this retrospective study, we aimed to investigate the
appropriateness of TM requests in our hospital. Patients in the study were identified from the TM requests for 3 months between
June–August 2004, using the laboratory database. A total of 2249 patients (1351 men, 898 women) were included in the study
and there were 6570 TM requests. The number of requests were 1050 (16%) for Carbohydrate Antigen 19-9, 993 (15.1%) for Cancer
Antigen 125, 941 (14.3%) for Prostate Specific Antigen, 921 (14%) for free PSA, 925 (14.1%) for Cancer Antigen 15-3, 788 (12%)
for Alphafetoprotein, 730 (11.1%) for Carcinoembryonic Antigen and 222 (3.4%) for AFP/Human Chorionic Gonadotrophin. Our findings
support the idea that for the evidence-based use of TM requests the education of clinical staff is required. Clear clinical
guidelines including recommendations about the appropriate use of TM can be useful for this education process. Careful audit
studies are also useful to determine the impact of these guidelines on the practice of evidence-based laboratory medicine. 相似文献
84.
Two silkworm strains viz, B20 A (high cocoon shell ratio) and C.Nichi (low cocoon shell ratio) were sib mated for 10 generations to determine the homozygosis. Both bulked segregant analysis(BSA) and near isogenic lines (NIL) studies were done to identify the RFLP markers closely linked to cocoon shell parameters. Three hundred and fifty-two random clones were identified as the low copy number sequence and used for identification of Restriction Fragment Length Polymorphic (RFLP) marker linked to cocoon weight and cocoon shell character. In the bulk segregant analysis, DNA from the parents (B20 A, C.Nichi), F1 and F2 progeny of high shell ratio (HSR) and low shell ratio (LSR) were screened for hybridization with the random clones. Polymorphic banding pattern achieved through southern hybridization with different probes indicated the probable correlation of polymorphism with high and low cocoon shell character which are possible landmarks in identifying the putative marker(s) for the cocoon shell character. Out of the 100 probes tried with parents, F1, F2 and their bulks, 10 probes were found to be closely linked to cocoon shell characters. 相似文献
85.
We describe the “somatic marker hypothesis” proposed by Damasio (1996) to account for the ability of most people to make decisions quickly and continually in the course of their lives. We relate this hypothesis to two other theoretical constructs, emotional orientations and purposes, which we have used in our research on students' reasoning and teachers' decision making. Given that somatic markers are a part of unconscious mental activity, they cannot be observed by introspective reflection. How then can we research something we cannot see? Beginning with the hypothesis that somatic markers influence actions, we observe, particularly, the actions of student teachers, teachers and children in mathematics classrooms at points where they make decisions. This process is illustrated through examples both of teaching and learning in mathematics, and through the account (see Op't Eynde and Hannula, this issue) of ‘Frank’ reflecting on his decision-making in mathematical activity. We use the case of Frank to illustrate some differences between viewing mathematical activity from our perspective and from those of some other contributors to this special issue. The connections between emotional orientations, somatic markers and purposes are further illustrated by two examples drawn from our research into teacher development and students' reasoning processes. 相似文献
86.
舒元梯 《乐山师范学院学报》2002,17(4):26-29
拓扑指数P1,S1和S2是表征饱和一元羧酸分子大小,支分度,形状等结构等结构特征的重要参量,本提出了计算饱和一元素羧酸物理化学性质P的定量公式,预测了含18个碳原子以内的饱和一元羧酸的相对密度,分配系数,熔点,沸点,在水溶液中的p^ka值和在水中的溶解度等6项物理化学性质。 相似文献
87.
廖慈惠 《孝感职业技术学院学报》2003,6(2):49-53
语篇标记作为语义性连接纽带的有形衔接是连贯的外在形式,起着表明说话者或作者的态度、意图或倾向等的作用。文章主要论述语篇标记的类别、语法形式、语文特征及逻辑语文关系等内容。 相似文献
88.
针对英语和汉语中重构性话语标记语频繁使用的情况,基于对所收集语料(主要为学术性文章)的统计分析,本文分别从语法和语用两个方面对英语和汉语中的重构性话语标记语的使用进行了分析;探讨了两种语言中重构性话语标记语在语法形式和语用功能方面的异同。 相似文献
89.
Santosh C. Das Aminu Z. Mohammed Sani U. Al-Hassan Abraham A. Otokwula Uche P. Isichei 《Indian journal of clinical biochemistry : IJCB》2007,22(2):79-83
In order to see the pattern of changes in differential serum lipid and lipoprotein fractions as a risk marker of coronary
complication in paired ‘maternal—neonate’ blood samples in an iodine deficient zone, 26 pregnant women and their corresponding
new born infants at term delivery from the iodine deficient Bassa region of Plateau state, Nigeria were assessed and the results
were compared with those seen in a similar 44 group of women and their newborns assessed in non lodine deficient region of
Jos. The serum thyroid function and lipid and lipoprotein profiles were determined by ‘ELISA’ and ‘enzymatic’ methods respectively.
Urinary iodide excretion level was also measured in 14 pregnant women in Bassa, 23 pregnant women in Jos and 16 non pregnant
control from Jos. Results indicate that the pregnant women assessed in Bassa were iodine deficient (P<0.01) and their thyroid
status was strikingly reduced as reflected by a drop in serum level of T4/TBG ratio (P<0.01) and a rise in TSH (P<0.005) in
comparison to that seen in Jos. There was marked hypertriglyceridaemia and total hypercholesterolaemia (P<0.005), with differential
significant rise in LDL cholestotol fraction (P<0.005) in the women assessed in Bassa as compared to Jos. The HDL cholesterol
however dropped less significantly in the group (P<0.05) with a concurrent marked rise (P<0.001) in the serum ratio of LDL
cholesterol/HDL cholesterol, total cholesterol/HDL cholesterol and triglycerides/HDL cholesterol in the lodine deficient group.
A similar pattern of changes were seen in the corresponding neonates in the Bassa group as compared to Jos group. It is concluded
that the pregnant women and their newborn offsprings living in a longstanding environmental iodine deficiency run a higher
risk of developing coronary complications than those living in non endemic region. It is striking that such newborns surrounded
by a continued state of lodine deficient may at a later adult-period of life develop marked risk of coronary complication
and other features of hyperlipidaemias associated with varying thyroid insufficiency and accompanied iodine deficiency disorders.
Prophylaxis measures as intervention has been highlighted. 相似文献
90.